Ben Affleck’s political thriller “Argo,” which opens nationwide on Friday, is already generating early Oscar heat for its complex characters and storyline. But the real story behind the movie is even more complex -- much more, in fact. And one Brooklyn-based documentary filmmaker wants to fill you in on all the details that Affleck missed.

Loosely based on a real-life covert mission, “Argo” tells the story of Tony Mendez (played by Affleck), a C.I.A operative who disguises six Americans as filmmakers and smuggles them out of Tehran during the Iran hostage crisis of 1979-81. In the movie, Mendez and the captives pretend to be working on a Canadian science-fiction film called “Argo,” but in real life, the fake movie was not originally called “Argo.” It was called “Lord of Light,” a screenplay based on the popular 1967 sci-fi novel by Roger Zelazny.

The real-life screenplay, written by a struggling writer named Barry Geller, was never produced, and neither "Lord of Light" nor Geller is mentioned in Affleck’s film. This according to the Emmy-nominated director Judd Ehrlich, whose forthcoming documentary about the screenplay, “Science Fiction Land,” recounts the even truer story behind Ben Affleck’s quasi-true story.

“Argo” was adapted from a 2007 Wired magazine feature story by Joshuah Bearman, but Ehrlich has been working on his documentary for six years, conducting interviews and compiling archival footage. He doesn’t begrudge Affleck for beating him to the punch, but rather thinks “Argo” will help draw increased interest in his project and the backstory he’s trying to tell.

“It’s been kind of interesting to see the whole thing blow up in the press,” he said in a phone interview. “But we’re really excited about the movie. We think it’s going to help spread the word for us.”

And from the looks of things, Affleck's success will trickle down to Ehrlich. Concurrent with “Argo’s” release, Ehrlich launched a Kickstarter campaign, hoping to raise the $50,000 he needs to complete “Science Fiction Land.” And the campaign is off to a remarkable start, having raised more than $16,000 in just six days. He said the theme of the documentary -- which culminates with Geller’s efforts to create a theme park called Science Fiction Land in Aurora, Colo. -- lends itself seamlessly to the spirit of Kickstarter.

“Geller believed in putting technology in the hands of the everyday person,” he said. “This is the perfect kind of thing for crowdfunding.”

So what are some of the key elements of the backstory that Affleck leaves out? In the Hollywood version, the “Argo” screenplay is taken from a slush pile -- the fake production company buys the rights for next to nothing and builds the fake production from the ground up (and on a thoroughly implausible timeline). In reality, Mendez got his hands on Geller’s “Lord of Light” script -- along with production designs for the film drawn by the famed comic book artist Jack Kirby -- after the project fell through.

Naturally, then, “Argo” never mentions Science Fiction Land, which Geller had hoped to create out of sets from “Lord of Light.” The proposed theme park generated massive interest at the time, with officials in Aurora hoping their town was going to play host to the next Disneyland. But the whole thing fell apart in December 1979 after a mudslide of shady backroom dealings and alleged investor fraud turned the proposed tourist resort into a public relations nightmare. The theme park and the “Lord of Light” movie were both subsequently scrapped.

Meanwhile, it was right around this time that the real-life agent Mendez was hatching his plan to pose as a movie producer and rescue six escaped American hostages who were hiding out in the Canadian embassy in Tehran -- and that’s where Geller’s script for “Lord of Light” came in. The fake project’s name was changed to “Argo,” and the rest is history.

Geller himself was unaware of the role his script played in the rescue mission until 2001, when he was contacted by producers of the Bravo series “First Person,” which was shooting an episode on the event. On his website, he writes that he is “deeply disappointed” that Affleck’s version of the events omit “Lord of Light,” but he still commends Mendez’s bravery in carrying out the mission that saved six lives.

As for Ehrlich, he said he understands why Affleck’s team had to condense the complex story for the sake of theatricality, but he hopes that his documentary will restore the tale with some of those layered complexities that make it worth telling.

“There really is this overarching theme of the interconnectedness of things,” he said. “The butterfly effect. To me that’s the most interesting part of the story.”

As for what he plans to do with is documentary once it’s completed, Ehrlich has already started making his film festival wish list.

“Toronto would be great,” he said. “That’s where ‘Argo’ got its start. It would be nice to see it come full circle.”